Compressor



Jan 7,-1941. P. A. FRIEDELLIETAL 2,227,740

COMPRESSOR 2 Sheets-Sheet l Fil ed May 2, 1939 P. A. FRIEDELL EFAL Jan. 7, 19 41.

COMPRESSOR 2 Sheets-Sheet 2 Filed May 2. 1939 Patented .E'an. 7, lhdl UNITED STATES PATENT. oFFica COMPRESSOR Philip A. Friedell and Morley V. Friedeli,

' Oakland, Calif.

Application May 2, 1939, Serial No. 271,276

8 Claims. (Cl. 230-147) s and volumetric efficiency. This invention applies particularly to fluid-actuated and fluid. moving devices in which a piston moves through an'orbi-tal path about the axis of the cylinder whilethe piston is maintained against rotation but permitted an oscillating movement about its axis.

This invention is-adaptable for use as a compressor for service station, shop and allied uses; as a gas compressor for refrigeration systems, chemical processes, as also for insecticide and paint spraying; as a vacuum pump for use in elec-v tric lamp and radio tube manufacture and in chemical and other processes, and in all cases where compression or expansion of gases is to be conducted.

The objects. and advantages of the invention are as followed First; to provide a planetary-type piston with an abutment which coincidently functions as a discharge valve to insure complete cut-ofi during the intake period of operation.

Second; .to form the discharge port in the cylinder with a minimum area and volume to reduce secondary flash-back to a minimum.

Third; to provide an aumliary discharge valve for the purpose of restricting the discharge port to minimum volume.

Fourth; to provide an auxiliary discharge valve of mammum lightness and strength and which coincidemtly reduces the effective volume of the discharge port.

Other objects and advantages of the invention will'become apparent as the following description is read on the drawings forming a part of this specification, and in which similar reference characters are used to designate similar parts throughout the several views, of which:

Fig. 1 is a fragmentary sectional elevation through a compressor showing the invention incorpoiiated therein, and corresponds to a section 5 taken on line l--l of Fig. 2.

ing the valve action, and in which Fig. 7 shows the piston and abutment at the initial intake and final discharge position; Fig. 8 shows the Piston in the position in which the abutment hasv reached its maximum discharge-port-closing position; Fig. 9 shows the piston and abutment in their intermediate positions with the abutment just ready to start opening the discharge port, and Fig. 10 shows the piston and abutment in the position in which the abutment has reached 10 its maximum discharge-port-opening position.

The usual planetary or oscillating piston type compressor includes a cylinder It having heads M and it in which an eccentric shaft l3 having an eccentric it is axially and revolvably mounted, and with a piston I operating on the eccentric. A suitable abutment is either pivoted in the cylinder wall, in the piston, or in the heads within the confines oi the cylinder, and functions to form a partition betweenthe intake and discharge ports as also to maintain the piston against rotation while permitting an oscillating motion thereof.

This invention utilizes an abutment it which has its opposite ends pivoted in the heads it and (335 62 as shown at Ill and it, and the pivots are illustrated as forming an integral part of the abutment although not restricted to this particular construction.

This abutment is slldable in a slot it formed BBQ preferably radially in the piston, although it will operate in a chordal slot, and this abutment has an arcuate face which bears in an arcuate seat 28 formed in the inner peripheral wall 22 of the cylinder it, the arcuate face and seat being formed to a radius having its axis coincident with the axis of the abutment pivot.

The structures so far described are all well known in the art and form a part of the invention only in combination with other structures in and modifications described in the following.

The invention resides in the utilization of the abutment as a mechanical discharge valve to prevent all primary flash-back, in combination with the discharge-port chamber of minimum M volume to restrict secondary flash-back to an absolute minimum, and an auxiliary valve for the discharge port chamber which valve is of maximum lightness and strength and least resistive to escape of discharge gases, and which valve, due to its specific form further restricts the volume or the discharge port chamber, and it also resides in the sealing means for the abutment and the relieving means for freeing the slot u of-entrapp d oil to prevent hammering.

valve 40, if it is of higher pressure than that in the space 53, escapes into this space 53 and forms the secondary flash-back, but being of minimum volume, has little eiiect on the mechanical eflie ciency and none whatever on the volumetric elliciency of the compressor, since this entrapped gas cannot escape hack. to the new intake charge of gas.

Further movement of the piston to a position m just ahead of the three-quarter position indicated in Fig. 10, opens the valve fully, and in this position of the piston, the discharge corner $7 of the abutment has reached the other terminal of its arcuate movement and is in registry with the 115 follow side 59 or the discharge slot; the majority of the compressed gas in space 53 has been discharged through the passage and past the check valve to, except in case of compressing to very high pressures, and the intake space is filled with new gas at atmospheric pressure.

As the piston moves to complete its cycle, the abutment is moved to close the discharge slot, and the final closing movement is very rapid; the valve being fully closed when the piston cooperates with the point located on the cylinder wall at the discharge edge oi the abutment, thus completely discharging all compressed gas from the cylinder and sealing the discharge port as shown P in Fig. 7, thus entirely obviating primary flashim back to the intake. I

As a vacuum pump, the operation is the same,

except that the intake charge is below atmospheric pressure and is driven out through the discharge, and since there is practically no resistance to overcome, and since the discharge is thoroughly sealed against primary flash-back, vacuum-pumping emciency is very high.

As will be understood, any primary flash-back escapes into the entire displacement space and reduces the volume of new gas taken in, as this flash-basis has direct communication with the intake pcrt tii, thus reducingv the volumetric emciency; since there can be no primary flash-back in this compressor, there can be no reduction in P volumetric emciency which approximates 100%.

It will he understood that variations in construction and arrangement of parts, which variations are consistent with the appended claims,

may be resorted to without detracting from theit spirit or scope oi the invention, or sacrificing any of the advantages thereof.

We claim:

1. An oscillating compressor comprising a cylinder having heads and provided with an arouate abutment seat with the axis of the'seat located within the confines of the cylinder, and an abutment pivotally mounted within the interior confines of said cylinder and seating in said seat and a. piston slidably cooperating with said abutmerit; an inlet port for said cylinder; a discharge port formed in the cylinder wall within the confines of said seat and closed by said abutment at the point of final discharge of gas and duringv the first portion of a cycle of piston operation and opened during the remainder of a cycle, ob-

viating primary flash-back following discharge of' gas from the compressor; and a discharge passage and a chechvalve therefor for said discharge port restricting secondary flash-back to a mini- 7d mum; said discharge port having parallel walls for creation of minimum volume of discharge passage and being formed throughout the length .of said cylinder and having a circumferential width measured on said seat equal to substan- 75 tially one-half oi the arcuate movement of said abutment on said seat, said seat being otherwise continuous and free of interruptions or openings, whereby maximum efiective discharge area is provided for discharge of gases'while providing fully effective sealing means between th intake 5 and discharge sides of said abutment.

2. An oscillating compressor comprising a cylinder having heads and provided with an arouate abutment seat with the axis of the seat located within the confines of the cylinder, and an m abutment pivotally mounted within the interior confines of said cylinder and seating in said seat and a piston slidably cooperating with said abutmerit; an inlet port forsaid cylinder; a discharge port formed in the cylinder wall within the con- 15 fines of said seat and closed by said abutment at the point of final discharge of gas and during the first portion ofa cycle of piston operation and opened during the remainder of a cycle, obviating primary flash-back following discharge of gas 2@ from the compressor;-and a discharge passage and a checlrvalve therefor for said discharge port restricting secondary flash-back to a minimum; said discharge passage being formed with proportionate cross-sectional areas. in conformity All with the proportionate volumes of gas discharged through the various areas, whereby the volume of said chamber, is restricted to the minimum requirements as specified, without sacrifice of port area requirements; said check valve limiting sec- 55% ondsryfiash-baclr to that of the volume of said passage.

3. In a compressor having a piston having an abutment slot formed therein, an eccentric rotatahle in said piston, a cylinder having heads,

and having an arcuate abutment bearing seat formed in the inner periphery thereoi' and an oil supply for sealing and lubricating the interior of said compressor; an abutment pivotally mounted in said cylinder and having a discharge side and an intake side and having an arcuate face bearing on said seat and having its axial ends pivoted in said heads; a discharge port on tending throughout the length of said cylinder and formed within theconfines of said seat; said discharge port including a discharge chamber and a discharge passage having a valve seat and varying in cross-sectional area as measured in planes transverse to the axis of the cylinder in m accordance with the proportionate volume of gas moving therethrough at any plane of cross-section, during discharge of gas from the cylinder; said discharge passage having minimum necessary volume communicating with said chamber 55 and a segmento-spherlcal valve for said passage and means for limiting the lift of said valve; said port having its leading wall aligning with the discharge side oi said abutment when said piston is in its final discharge position and thereby comw pletely obviating primary flash-back of gas to the cylinder; said valve having universal seating characteristics and functioning by its spherical undersurface projecting into the discharge passage to restrict the volume of said chamber to to reduce secondary flash-back to a minimum.

4. In a structure as defined in claim 3; said abutment having its intake side formed with a relief intermediate its length and extending throughout the major portion of the length thereof and having its undersurface beveled in the direction of said relief to assist in the discharge of oil from said slot into the intake side (iii , of said compressor between the piston and cylinder walls for oil sealing the operating clearance between the piston and the cylinder andto eliminate hammering oi the abutment on the bottom of the slot through an entrapped body of oil.

5. In a compressor having a cylinder having a wall with an arcuate seat formed in the inner surface of the wall and an abutment seated in said seat and a discharge port opening into said seat and controlled by said abutment, a discharge chamber having a valve seat and a valve therefor; said chamber having a maximum cross-sectional area at one point only equal to the area of said port with the cross-sectional area decreasing from said point in accordance withvthe proportionate volume of gas passing during discharge, to substantially zeroarea at the end of the cylinder, whereby the volumeeof gas available for secondary flashback or re-expansion is reduced to an absolute minimum.

6. A structure as defined in claim 5 in which said chamber comprises a bore extending through the length of the cylinder wall with one side of the bore opening into said port close to said seat and with a tapered member mounted in said bore and decreasing the cross-sectional area of said bore gradually from that o! the area of the port to substantially zero area.

'7. In a gas pump cylinder having an intake and an arcuate abutment seat and a discharge port opening through said seat, an abutment seating in said seat and mounted in such manner as to be capable of moving to alternately uncover and cover said discharge port and a piston operating in said cylinder and cooperating with said abutment to cause said abutment to alternately uncover and cover said discharge-port; a bore formed in the wall of the cylinder parallel to the axis of said abutment seat and opening into said discharge port close to the opening of the port through the seatfa check valve for said bore; and a tapered member mounted in said bore and gradually reducing the cross-sectional area of the bore from that of the discharge port to substantially zero between its ends, whereby upon discharge of gases by said piston from said cylinder past said check valve, a minimum volume of gas is retained between the valve and the abutment form-expansion in said cylinder when said abutment uncovers said port for discharge of another volume of compressed gas from said cylinder.

- 8. In an oscillatory compressor having a cylinder wall provided with an arcuate abutment seat port opening through said seat and controlled by said abutment; a bore formed through the length of said cylinder parallel with and'communicating and an abutment seating therein and a discharge 

